Simple steps for avoiding infections from dogs and cats

Lloyd Resnick

Former Editor, Harvard Heart Letter

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“Ugh! I’ve been kissed by a dog! I have dog germs! Get hot water! Get some disinfectant! Get some iodine!”—Lucy, after being licked by Snoopy in A Charlie Brown Christmas

Americans share their households with an estimated 140 million dogs and cats. For the truly pet-centric among us, these creatures are family members, plain and simple. In addition to delivering that most elusive unconditional love, pet ownership confers several health benefits—including lower blood pressure and cholesterol levels—and increased opportunities for exercise and socialization.

Lucy may have overreacted after being smooched by Snoopy, but dogs and cats can transmit disease to people, either directly through licks, bites, and scratches; indirectly by carrying other infection-laden critters like fleas and ticks into the human environment, or by shedding tiny infectious organisms into our environment through feces. As a group, these diseases are called zoonoses (ZOH-uh-NOE-sees).

Most of the diseases we pick up from dogs and cats arise from bacteria, single-celled and wormlike parasites, and one virus (rabies). People with compromised immune systems (such as those with AIDS or those taking drugs to ward off rejection after receiving an organ transplant) and kids are at the highest risk of becoming sick with such ailments

The list of diseases transmissible from dogs and cats to people is quite long, but the risk of getting sick from such conditions is low—especially if you take a few simple precautions.

Beware bites, scratches, and smooches

While it is more likely that you’ll receive germs causing human disease while shaking hands than when getting smooched by a dog, saliva from a cat or dog—delivered via an affectionate lick, an accidental or aggressive bite, or a defensive scratch—may contain organisms that can cause illness if they penetrate the skin or come in contact with the mucous membranes of the mouth, nose, or eyes. The dog or cat that unknowingly transmits these germs usually shows no signs of illness. But once inside a human, these bacteria can cause skin infections, flu-like symptoms such as fever and chills, and more serious diseases such as meningitis.

The rabies virus is the most dangerous saliva-borne germ a cat or dog can bestow on a person. Thankfully, rabies in people is very rare in the U.S. (only 47 cases were reported between 1990 and 2005), and most of those cases are attributed to bites from wild animals such as bats and raccoons. One reason dogs and cats so rarely transmit rabies is our nation’s highly effective pet-vaccination programs.

A fastidious cat that cleans its paws with its abrasive tongue can transfer bacteria belonging to the bartonella family from its mouth to its claws. In such a case, a bite or a scratch can cause cat-scratch disease, which usually causes localized lymph node swelling near the injury site but can progressively affect the liver, eyes, or central nervous system.

Here are a few ways to avoid saliva-borne infections:

  • Socialize your pets with people so they are less likely to bite and scratch.
  • Thoroughly wash any bite or scratch wound with soap and water. Watch the area for swelling and redness. Puncture wounds should be seen by a doctor.
  • Make sure your pets are vaccinated against rabies. This is a legal requirement in most states.

Poop patrol

No one in their right mind intentionally touches or ingests dog or cat poop, but people can nevertheless expose themselves to several nasty disease-causing agents from it via contaminated soil or water. These include salmonella, a bacteria that humans more commonly get from contaminated food, and giardia, a single-celled parasite that can cause severe diarrhea.

Also, the eggs of intestinal worms—including roundworms, hookworms, and tapeworms—are commonly shed in animal feces, and people who accidentally ingest them can get become ill. Only the tapeworm can develop into an adult parasite in the human intestine, but the other worms in immature form can migrate to the skin, eyes, and other organs.

As if that weren’t enough, cat feces can carry a microscopic parasite (Toxoplasma gondii) that causes enlarged lymph nodes. Infected people usually don’t show symptoms, unless they have a weak immune system. Most important, women infected with toxoplasma during pregnancy can transmit the parasite to their developing fetus.

Here are a few precautions to take:

  • Make sure your pet gets an annual veterinary physical
  • If your pet develops diarrhea, treat it promptly.
  • Wash your hands thoroughly after cleaning up dog or cat feces and after gardening or exposure to soil that may harbor canine or feline fecal matter.
  • If you’re pregnant, have someone else clean out Felix’s litter box.

Freeloading fleas and ticks

The fleas and ticks that get a free ride and feed on domestic dogs and cats can also feed on humans, though they prefer hairier mammals. During feeding, those insects can transmit the germs that cause Lyme disease, ehrlichiosis (characterized by fever and headache), the malaria-like infection known as babesiosis, and even plague, most human cases of which occur in the Southwest U.S.

Follow these tips to stay insect free:

  • Use a veterinary-recommended flea- and tick-prevention product on your pet.
  • Check your pets for fleas and ticks regularly, even if they are on a preventive.
  • If your home is flea-infested, treat the indoor environment as well as the pet.
  • If you find a tick on your pet or yourself, remove it promptly and wash your hands afterward.

The bottom line with pets, people, and disease is this: Practice good hand washing and other common-sense personal hygiene measures, and give your pets good veterinary care. That will further reduce the already low risk of getting an unwanted ailment courtesy of your “best friend.”


  1. Johnathan Mathis

    Its like i tell my wife all the time when we visit her parents, dont kiss the dog. However, some of this seems like a lil much. I find it hard to believe that pets can have this many diseases and people are suffering more. I mean think about it, its very common to see people kissing their dogs. Thanks for the article though, something to think about.

  2. Melih Acikbas

    Thanks for nice post. I love animals but some infections are dangerous. Especially for kids.

  3. como incrementar la masa muscular

    Have a well trained dog will also help in making sure that your pet does not bite someone and pass on an illness.

  4. Alfred Finch

    Oh thank you very much for the info, my dog ​​is grateful to you rita

  5. Vicky

    A great bit of info for anyone that loves pets.

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  8. Steve Badum

    Have a dog and a cat and its a bit scary what you have posted, you just look at them as family member and forget what might be hiding in that fur or mouth. you can insure your pet for any problems too online in minutes there are heaps of sites, here is an example below, but first thanks for sharing this information about our pets 🙂

  9. Whirly Dog Supplies

    great article. we all can use a refresher on personal cleanliness. i noticed a reply from “mary” and her father being diabetic… people with compromised immune systems should be especially careful in handling dogs, and see immediate medical attention when bitten by a dog. and it’s a good example that the owners of dogs need to be responsible!

  10. Anonymous

    I have had dogs for the past thirty years. They have provided so much joy to me, but once in a while they have brought some interesting things into the house. Good cleaning and hand washing has prevented any problems here. Great post with helpful information.

  11. Colin Thomas

    A great bit of info for anyone that loves pets. I will certainly be coming back, have book mark page.
    Great Post

  12. Chris

    I love my girlfriends dog, but when i had to remove a tick from his neck that was when i really started itching, wondering how much more he had bought into the house, germs, fleas, ticks oh no i’m starting to itch again now!

  13. jusman

    Hi,..Nice Blog.

    Talking about Animals [cats and dogs] I like These animals. they are too cute. I love them like my family.


  14. Carlos

    No doubt that this blog makes a difference. I read it almost every day and I always find a lot of new and interesting information.

  15. itslip

    Oh thanks you so much for giving us this relative information about dog infractions this is relay imported information,

  16. Mary

    my father’s hand was bitten by a dog one time and he is a diabetic. It took six rounds of antibiotics and he could have lost some of his fingers from the bacteria from the bite. People definitely need to pay attention to your tips about proper hygiene when dealing with animals. You have a lot of good information that should make anyone think before dealing with any animal.

  17. Anonymous

    This is important and often overlooked information. I experienced an infection that could have been easily avoided. Thanks for putting this out there.

  18. Marta Márquez

    Most of the people who have pets know what should they do, but this rules are not complete. I have a dog and all her vaccinations are up to day, she has drops for fleas and is not difficult she can be contaminated in the park by the grass or by other animals. So I must be very careful with her.


  19. NVQ courses

    After reading about the poor lady who died of rabies in the UK, I’m more aware of diseases from cats and dogs.

  20. Ben

    I really love pets specially dog,Actually I have 2 dogs at home so this information really important for me and Im sure I may apply this . So thanks!

  21. Ron

    I agree, if owners would just make sure that they do regular vet visits so true.

  22. Pau-Papasan

    Dogs and cats could transmitt infections, but certainly the great risk are birds, these class of animals are really dangerous…

  23. yiezx

    there are many article gives benefit

  24. yiezx

    thank you this is gratitude lovely article


  25. anupom

    I admire this post! It’s nice to see many questions answered in a blog post like this.

  26. Andrew James

    Thank you for that very informative post. Our company has an office pet and it’s great that we have this checklist to follow to make sure we don’t acquire any diseases from it in the future.

  27. drh

    As we all know pets continue to move from the ‘backyard’ into the ‘bedroom’. Because of this revolution Zoonotic diseases continue to be a veterinarian’s primary concern especially when small children in the home. Current pet interactions are noted below.

    • In the United States, >60% of households have pets
    • Among dog owners, 53% consider their dog to be a member of the family
    • A surprising 56% of dog owners sleep with their dog next to them; ≈50% of dogs sleep on the bed
    • Among cats, 62% slept with their adult owners and another 13% slept with children

    Along with the information contained in Mr. Resnick’s informative article many internal and external parasites may be easily managed with a monthly Heartworm Preventative. Ask your veterinarian to recommend Heartworm, Flea and Tick products that are most appropriate for your home state.

  28. Great informative post

    I have 3 dogs myself so I know they can get a little unruly but what I have said to my children is DONT LET Bengy Sammy or Suzy Like your face

    I hope its ok if I leave my squidoo blog address here if not I understand P.s its not a spam site its all about getting traffic to websites like yours and mine In exchange I will post your like on my site.

  29. Anonymous

    wow great informative post..
    I’m a animal lover and I always keep my little kitten in check..
    After reading your post I’m even much more cautious..

  30. Dany

    Thanks for info. I love animals.

  31. butterfly

    some good steps to consider , as we all know how much diseases they can bring even though we can’t live without them

  32. Katie Reese

    This was a great article. People just need to be more cautious when taking care of themself and their pets.

  33. Allan Jensen

    Dogs are a great healp benifit to humans and help keep us healthy, and active.

  34. Tyler Anderson

    I have have never realized how many different illnesses animals can pass to humans.

  35. Peta Williams

    Never realized the danger of infections from pets, I am alway telling my kids about basic hygiene with hand washing after playing with the dog.

  36. Paul

    I agree with all the comments… Many people don’t take care of their pet, nor themselves! It really is about good personal hygiene… thank you for sharing this article… good stuff!

    Thank you again!!!

  37. Anonymous

    Basic hygiene with hand washing and common sense will avoid most diseases passed from pet to human. When you board a pet though, they can be exposed to diseases from other animals in the facility. Checking out the facility ahead of time and asking questions are essential when choosing a dog boarding facility.

  38. garden boy

    Take care of your pets everyday to avoid sick..dont turn to them only on weekends

  39. flea pictures

    Wow, I never realized how many infections people could get from their dogs, guess it’s time to start being a little more aware around my pup!

  40. Tyler Anderson

    Have a well trained dog will also help in making sure that your pet does not bite someone and pass on an illness.

  41. Abby Shaver

    I agree, if owners would just make sure that they do regular vet visits their pets will be so much healthier!!

    • Anonymous

      You are so right. Cleanliness is the name of the game when it comes to looking after our pets and bringing them inside

  42. Mike Williams

    Socialization is a great thing. It will help your animal be more comfortable around other people and their kids.

  43. Sarah from Alkaline Benefits

    There are many ways to reduce risk of getting a transmitted disease from your pet. However, even with all the precautions, it’s still good to be aware as you can never predict what will happen no matter how much preparation you make.

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    Beware of the diseases that bring from some animals, for pregnant women please stay away from animals until your baby is born.

  45. now, I have to be more caution to my cat because they bring many illness and I hope I don’t get any of them. thanks for the tips, it’s very useful, they’ll become my preventive actions in the future.

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    The dog and cat owners that forget to take their pets to veterianary regularly are calling for sickness. Taken care of your pet as require will help avaid unnecessary diseases. Buy assurance insurance for your pet as well.

    • Mihai

      A cat with FIV will live over 15 years, the most important thing to do is to feed a GOOD food to keep up what’s left of their immnue system.Also treat the problems as they arise. Which are runny eyes, dry coat and/or mouth problems.Having Lysine on hand for the runny eyes is a good idea. Most FIV cats have the herpes simplex virus and being on 250 500mg of lysine (on their food) a day for a week can clear up the runnynes within a few days. I’ve heard of people using Transfer Factor, as a supplement, to help the overall health as well. But mostly it’s the good food that’s needed. BTW there are two very good FIV cat lists on Yahoogroups, come on over and join. The owners there all have FIV cats in every stage of the disease. Most cats stay asymptomatic most of their lives.

  47. Alun

    Ah so many things to worry about when keeping animals. My cat brings all sorts of things into the home, but what can you do eh? 🙂


    • John

      Pet Lovers always have this fear of getting bitten by their very own pets and passing the disease to them. This article really explains this issues and teach you how to prevent this from happen. All the pre and post prevention. I simply love this post.

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